Digital Signal Processing Reference
In-Depth Information
6
4
2
0
−2
−1
0
1
2
3
4
5
6
(a) Composite Sample Range n
6
4
2
0
−2
−1
0
1
2
3
4
5
6
(b) Composite Sample Range n
Figure 2.4:
(a) First sequence, with postpended zeros at sample times 3, 4, and 5; (b) Second sequence,
with prepended zeros at sample times -1, 0, and 1.
We make the call
[y, n] = LVAddSeqs( [3,-2,2], [-1,0,1], [1,0,-1], [0,1,2] )
which yields
y
= [3,-1,2,-1] and
n
= [-1,0,1,2].
We can illustrate use of the function
LV MultSeqs
by using it to multiply the same sequences.
We thus make the call
[y, n] = LVMultSeqs( [3,-2,2], [-1,0,1], [1,0,-1], [0,1,2] )
which yields
y
= [0,-2,0,0] and
n
= [-1,0,1,2].
2.4.3 THE UNIT IMPULSE (DELTA) FUNCTION
The
Unit Impuls
eor
Delta Function is
defined as
δ
= 1 when
n
= 0 and 0 for all other values of
n
.
The time of occurrence of the impulse can be shifted by a certain number of samples
k
using the notation
δ
[
n
]
[
n
−
k
since the value of the function will only be 1 when
n
-
k
=0.
The following function will plot a unit impulse at sample index
n
on the sample interval
Nlow
to
]
Nhigh
.
function LVPlotUnitImpSeq(n,Nlow,Nhigh)
